I've been checking the code on this, since I cannot fix it so far.

It has to be this:

                Dim arrFiles As ArrayList = GetFiles()

                For intItem = 0 To arrFiles.Count - 1

If GetFiles returns an empty array.

GetFiles uses DataCache.GetCache

The speed at which the page reloads indicates it is not a usual app restart.

But it might be that the Cache is being purged to free up memory.

Or, looking at the web.config, it might be because:

~\Providers\CachingProviders\FileBasedCachingProvider\

and

~\Providers\CachingProviders\BroadcastPollingCachingProvider\

are missing in my site.

I'm going to try this now.